Greater precipitation intensity and variability will increase the risks of flooding in many areas because of climate change. Developing countries are especially vulnerable to these effects of climate change, because of their existing exposure to an already fragile environment and their economic and social sensitivity to climate change. The conventional systems of planning methods in flood management, in particular infrastructure planning, can not be directly applied to climate change adaptation under an uncertain and changing climate. The study aims at proposing planning methodologies of climate change adaptation in flood management through reviewing the projects of Japan International Cooperation Agency (JICA). The agency started development assistance projects of climate change adaptation in developing countries. The study examines prediction methodologies of climate change effects on perception causing floods and droughts. To deal with the uncertainty of prediction, some range of future perception should be considered. It is predicted that flood peak volume increase by 25 – 50% in 2050 in a Metro Manila suburb area because of impacts of both climate change and urbanization, and by 10-20% in Tagologan River Basin in the Philippines. It was found that the conventional methods of flood management of mainly structural measures have a limitation to adapt climate change. Instead of constructing long dykes from river mouths to mountains, more flexible measures should be developed. These measures include land use regulation, community-based disaster management, reservoirs in urban area, and levies protecting only strategic areas.